The ‘electric cars aren’t green’ myth debunked

It’s time to bust this thing wide open.

‘Electric cars aren’t green’ is a great bit of counter-intuitive headline bait, but it’s bad maths. This is how the argument goes, again and again…

Electric cars have higher manufacturing emissions than normal cars. Electric cars also use electricity that has its own footprint. And put together these two factors are a ‘dirty little secret‘ that negate any climate benefit of electric cars!

No. Let’s clear this thing up once and for all.

It’s all about the juice

One of the most irritating things about articles discussing electric car emissions is the way it’s always very black and white. In one corner you have the ‘zero emissions’ brigade and in the other the ‘worse than combustion engine’ crew.

But as ever, real life comes in shades of grey.

The reality is that even after you account for the bigger manufacturing footprint of an electric car it is all about the fuel mix of the power you use, the ‘juice’ if you will.

Using coal powered electricity electric cars do nothing to cut emissions, using natural gas electricity they’re like a top hybrid and using low carbon power they result in less than half the total emissions of the best combustion vehicle, manufacturing included.

Mapping electric car emissions

The following map compares the carbon footprint of electric driving using average grid electricity in 40 or so countries. The actual carbon intensity of electricity you use may differ from the national average for a number of reasons, but it’s a great starting point.

The results are shown in terms of grams of equivalent carbon dioxide per vehicle kilometer (g CO2e/km). Each estimate includes emissions from vehicle manufacturing, power station combustion, upstream fuel production and grid losses.

The specs are based on a full electric vehicle, similar to a Nissan Leaf, using the 2009 average fuel mix in each country. For each country vehicle manufacturing emissions are assumed to be 70g CO2e/km, based on a number of studies detailed in the report.

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Of the 40 countries covered in this map emissions vary from 70g CO2e/km in hydro loving Paraguay, up to a 370g CO2e/km in heavy coal using India. The US average is 202g CO2e/km, in China it’s 258g and in Canada 115g.

In Paraguay virtually all the emissions are from vehicle manufacturing, as the power is incredibly low carbon. Whereas in India the breakdown is 70g for vehicle manufacturing, 200g from power plants, 30g for fuel production and a whopping 70g for grid losses.

The colors in the legend split the countries into five different groups based on carbon intensity. As you can see, even after vehicle manufacturing is included the carbon intensity of driving an electric car varies 5 fold based on the juice.

For a bit of reference, the average American gasoline vehicle is up at about 300g CO2e/km, while a new hybrid might manage 180g CO2e/km after you include vehicle manufacturing, fuel combustion and fuel production.

Compared to combustion vehicles

Because grams per kilometer is such a funny metric it is nice to convert these results to something more familiar. Working backwards from the data we can estimate what type of conventional vehicle (if any) would produce similar emissions.

For want of a better phrase lets call this the ‘Emissions equivalent petrol car’.

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Now the figures are much easier to get a grip on.

In coal heavy India, China, Australia and South Africa electric cars using grid power are just like typical gasoline vehicles, in the 25-30 MPGUS range. In the UK, Germany, Japan and Italy they are as good as the best petrol hybrids, in the 45-50 MPGUS range. But in low carbon supply places like France, Brazil, Switzerland and Norway they are in a different league, averaging well beyond 100 MPGUS for equivalent emissions.

It is important to remember that the electricity you get might not match your national average for any number of reasons. The night time intensity might vary, you might have solar panels or live in a country like the US, where the grid is actually a bunch of separate grids. For example in Colorado a grid powered electric car is equivalent to about 30 MPGUS, whereas in California it’s up around 70 MPGUS.

For all the comparisons in this map the vehicle manufacturing of a gasoline car is just 40g CO2e/km compared to 70g CO2e/km for the electric vehicle. This is because we have accounted for both a greater manufacturing footprint and lower lifetime mileage in an electric car.

If you are interested in the detail check out the full report. It includes a breakdown of all figures, sensitivities to manufacturing, vehicle performance and comparisons to diesel vehicles.

Electric cars are as green as their juice

Critics of electric cars love to talk about manufacturing emissions and putting horses before carts. But they never seem to offer any better solutions. If they were waxing lyrical about urban densification, electrified public transport and the joys of bicycles their critiques would ring true, but that’s not what you hear.

Electric cars are relatively new at a commercial scale and are dealing with issues of cost, range and charging speed. Each of which will be helped by improving batteries. Despite this they offer enormous hope for reducing carbon emissions, improving local air quality and limiting noise pollution.

Electric cars are far from perfect, and there are plenty of valid ways to critique them. But let’s not pretend that a gasoline vehicle can compete with an electric car in terms of carbon emissions. It’s just not a contest.

Give an electric car the right juice and it crushes combustion engines.

Author’s note: in case you are wondering, I don’t own an electric car. We have an efficient Skoda diesel which is mostly used at weekends with 4 people in it. My preferred mode of transport is my old dutch bike, which in terms of gCO2e/km trashes all comers (foodprint included).

I just would like to precise some information: 1.3 million electric cars
around the world in 2015, but they produced more greenhouse gases (GHG)
than if they were powered by gas or diesel! I analyzed carbon footprint
data and EV industry figures. Over half of electric cars in the world
are in the US and in China. Two countries where electricity is mainly
generated from coal (respectively 40% and 80%). So electric cars produce
there more carbon than their thermic equivalents. In 2015, electric
cars produced there 250 000 tons of CO2e more than if they had been
powered by gas or diesel.

Someone somewhere has forgotten to mention the tons of Lithium used in the production of batteries, and the thousands of gallons of Arsenic and Cyanide used in the industry. They still use petro chemicals in the production of the vehicle. No-one yet has a strategy for disposing of the batteries as they expire so no doubt they will be getting buried in caves somewhere waiting to self combust or leak into the planet!

Hamilton Hunter

Looking at buying a specialized vehicle like a metro based EV vehicle. How can i use it for normal trips and use as a SUV or pulling a trailer or any of the normal use of a vehicle? I have found that all EV owners that live outside of a 3-4 mile/day use of a car (most all of them) must have a gasoline powered vehicle for backup to do normal activities that we all do. How does that help the footprint? How can one afford to own what is at best a ‘specialized’ (e.g. EV) vehicle for use when the average commute to work is over half of the distance the EV charge capacity? (never!). Also, is it true that even the best battery/charging systems are about 80-90% efficient? If my batteries need a 10 kw-hr recharge i must put in 12 kw-hrs? Also, reading up on the battery lifetimes, the loss of capacity is about 50% over 5 years of driving 12,000 miles/yr (actual data, not going off of production hype)? If i get only 75 miles per full charge, and a charge takes 10 hrs to deliver, then my car is parked and being charged 1600 hrs (2 full months) of the year! Charging stations are the most non-green parking spot in the world as well. Some even try to use solar charging panels (with footprints as well) as a very poor green solution to using coal or oil fired power plants to charge their vehicle! EVs need much better batteries and much more range, IN COMBINATION with a green central source of electricity like nuclear power before EVs are ready to be prime time and take more of a permanent auto market. They are far far from that. Bio diesel and hydrogen powered vehicles were once thought to be the saving grace, EVs will go the same way. If you want convenience, low cost, low carbon footprint, buy a 65 mile/gallon gas vehicle. And free up the obnoxious waste of parking spaces by privileged EV owners that were subsidized by tax payers in cities. That is atrocious! If you want to go green, then buy a bike and ride in to work those few miles.

Adam Michaels

CO2 generation as a measurement of efficiency is absolutely not what any engineer or even a high school physics student would use to determine the efficiency of a system… especially a well-documented and researched system as combustion and electric motors.

you say its “bad maths” but there is no mistake that the best way to determine efficiency, in all its complexity as it already is on a permutation basis, would be to take the VERY STANDARD AND INCONTROVERTIBLE PHYSICS considering power in/out, motor load, energy loss, and then you have to account for overall production of materials and maintenance and forecasting in accounting for future production efficiency, etc.

The physics and the difficulties considering power plant generation, the efficiency of combustion motors and the reaction equations, chemical reactions and thermal dynamics, supply chain management and so many other things can and would occupy a competitive market with real considerations, but CO2 emissions as a determinant would either underdescribe efficiency (because it doesn’t have anything to do with efficiency) or it would be astronomically daisychained through many poorly understood causal relations that would be considered in climate change meteorology.

In the end, it would be VERY simple (although perhaps time consuming) to find and crunch these numbers and display them on your website in an easily digestible way with sources for reference. I suspect that you won’t be doing that any time soon.

Plainsspeak

What happens to the price of oil, gas and coal in China when America stops using it? You know, China, where they don’t have an EPA and don’t really care if they’re invited to your wine tasting parties?

Baddy

I’d like to thank all of you in these discussions for virtually eliminating my concerns of environmental impact of EV’s . I was a skeptic because main stream media has not bothered to prove or at least entertain comparisons of EV to fuel carbon footprints . Electricity has to come from some the same sources as our gas guzzling vehicles right ? , hence the skepticism . The second part of my concern was around the end of life cycle of EV’s , particularly lithium/ion batteries . I have always been pro clean energy and will now add EV’s to that equation !!

JM

I have a question. It has been stated that charging your E-vehicle is more efficient than using a gas engine. The figures shown for charging the e-vehicle are all straight-forward but do not represent the unused power that continues to be generated even though you are no longer using it…. it is there full time for your convenience. Yes, you pay more per kWh in money to cover the $ cost but my question is; how does the wasted energy that you did not use yet was produced, get accounted for in the real energy total used to charge your e-vehicle?

Jang Younghwan

This is a bad article. Even though the power plant uses fossil fuels, electricity can be distributed at night time by charging EVs. Fossil fuel power plant wastes electricity even though nothing uses electricity by idling, therefore using EVs can eventually reduce usage of fossil fuels.